We are planning on using the logo on both the web and in our mobile application. A large logo with text beside it is fine as long as a unique part of it can be easily extracted and used as the application's launcher icon (and needs to be somewhat recognizable at 36x36 pixels). Here's a link to the Android Launcher Icon Design guidelines that we will need to use when creating our icon from your logo:
http://developer.android.com/guide/practices/ui_guidelines/icon_design_launcher.html
Our application will integrate with several online billing systems. Currently, we support integration with FreshBooks, and we will be rolling out support for ConnectWise, Zoho, SalesForce, and more in future updates, and since most of our customers will be using one of these platforms already, it will help if it is similar (but we don't want a clone of any of these logos as we have plans to work with many of them and their logos are all completely different)